Furnace



June 16,1931. v. z. CARACRISTI 1,810,343

FURNACE Filed Sept. 30, 1922 4 SheetsSheet 2 v. z. CARACRISTI 1,810,343

FURNACE Filed Sept. 30 1922 June 16, 1931.

4 SheetsSheet' 3 I 25 28 INVENTOR 1 MRNEYS VIRGINIUS Patented J1me 16, .1931

warren. srarss Z.;CARAGRISTI, OF BRONXVILLE, NEW YGBK, ASSIGNOR TO LOCOMOTIVE PATENT orr cE PULVERIZED FUEL COMPANY, A CORPORATION OF DELAWARE summon Application filed September 30, 1922., Serial No. 591,919.

'Myin'vention relates to furnaces, and es 8 pecially to the construction of the combustion chambers of furnaces suitable for burning powdered or pulverized fuel, such as powg dered coal. I aim to simplify and cheapen such furnace structures; to make them strong without excessive weight; and also to provide for air circulation in them,in order to prevent overheating or to improve the thermal eificiency by the preheating of air for com- 7 bustion, or both.

How these andother advantages can be realizedthrough my invention will appear from my description hereinafter of the best embodiments of the invention known to me.

In'the drawings, Fig.' 1 shows a vertical section (front to rear)through' the combustion chamber of a steam boiler furnace for burning powdered coal, constructed in accordance with'my invention.

Fig.2 is a fragmentary view,'on a larger scale, showing a horizontal section through the furnace wall atone corner, taken as indi' cated by the line 2-2 in Fig.1.

Fig. 3 is a fragmentaryinside view of the" appears in sec;

side wall of the furnace, which tion' at the top of Fig. 2. I

Fig. i is a similar outside .view of the front wall, which appears at the left of Fig. 2.,

Fig. 5 is a fragmentary perspective view,

from inside, of a portionof the front wall as it might appear during erection, certain parts being shown in cross section. V I

Fig. 6 is a view generally similar to. Fig.

'5, illustrating certain modifications.

Fig. 7 is a fragmentary plan view of an incomplete wall, illustrating another modification. n

Fig.- 8 is a fragmentary view showing a horizontal section'througha furnace wall of, modified construction, taken as indicated by the line 8-8 in Fig. 9.

Fig 9 is a'fragmentary outside view of the 1 wall illustrated in Fig.8, partly in section as indicated by the line 99 in Fig. 8.

Fig. 10 shows a vertical cross section through the wall, taken as indicated by the on line 10-1O in Fig.8, with one course above the topmost one of'Fig. 9:

Fig. .11 shows a horizontal section through :ber near its front wall 16, through the roof 17, each such burner comprisingan inner fuel pipe or nozzle 18 with circumjacent air intakes 19 and 20. The burning air and fuel stream from the burner descends in the combustion chamber adjacentrthe front wall 16until its momentum is overcome by the fur nace draft, and then bends rearward and ascends through the rearportion of the combustion chamber, finally makingits exitup ward therefrom to the heating surfaces of the boiler,here shown as comprising banks of.

forward inclined water tubes 21 with their first tranverse upward pass directly overlying the combustion chamber. In the lower portion of the combustion chamber, some distance 'above the, floor 22, is a waterscreen shown as comprising. oppositely inclined blanks. of

' water tubes 23, connected to a common hori zontal, headerf24 attheir forward ends. In practieathese tubes 23. are so spaced that they'effectuallycool'the falling ash particles from the combustion zones above them below fusion or slag-forming temperature, so that on reaching the furnace floor 22 they shall not run together into one solid mass, but remam separate and easily removable.

The combustion chamber wall is double,

comprising aninner refractory or heat re-- sistant wall or shell 25 and an outer wallor shell 26, separated or spaced apart to afford an intervening air space 27 These walls 25 and 26 comprise brick or. blocks28 and29 laid lengthwise in horizontal courses, and arranged to break joints from course to course. The inner wall 25 isof extremely refractory material, while the outer wall 26 may be of ordinarily refractory material imerely,or

even of material not especially refractory, suchas ordinary brick. As shown, the inner wall 25 is of but very moderate thickness, in order that it may be effectually cooled by i the air in the interspace 27, and its inner surface thus kept below a temperature at which it would melt and run; while the outer wall 26 is thicker and more massive, so as to afford more strength and stability. In order that the walls 25 and 26 may efl'ectively reinforce and strengthen one another, they are interconnected and braced to one another, at intervals, by a multiplicity of ties in the form of extremely refractory cross-bonding blocks 30 extending between them, with their ends embedded in and forming part of each of the walls. As shown in Figs. 1 to 5, one of these tie blocks 30 is located at each joint in each horizontal course of each wall, so that tie blocks in adjacent courses are arranged in alternation. At the inner wall 25, the ends of the blocks 30 extend clear through between the blocks 28, flush with their inner surface; while at the outer wall 26, the ends of the blocks 30 (generally speaking) extend only part way through, being completely overlapped by reentrantly reduced ends of the blocks 29. The blocks 30 at alternate horizontal courses are arranged in vertical series, and the blocks of adjacent series are separated horizontally to afford vertical air passages 31 between the walls 25 and 26. Owing to the communication of each vertical passage 31 with those adjacent it permitted by the vertical separation of adjacent blocks 30 in each vertical series and to the alternation of the blocks 30 as between adjacent horizontal courses, zigzag horizontal passages for air are afforded between the walls 25 and 26.

It will be seen that not only do the two walls 25 and 26 reinforce and stabilize one another as walls by virtue of their interconnection by the blocks 30 extending between them, but that each vertical series of blocks 30 acts individually as a sort of reinforcing and stabilizing buttress or stiffening rib for each of the walls, by virtue of the mere rigid spacing apart of the alternate blocks of such series by intervening blocks (28 or 29) of the other wall.

As an additional means of reinforcing and stiffening the furnace, an external frame structure 33 may be provided for the outer wall 26. As shown, this framework 33 comprises a number of horizontally extending metal channel members 34 externally set into and anchored fast to the wall 26, over courses of its blocks 29 of substantially the same vertical width and correspondingly less horizontal depth. Against the wall 26, outside of the members 34, are vertical metal I-members 35 and 36, secured to said latter members at each intersection. The horizontal members 34 are secured to the wall 26 by means of metal anchor straps 37, doubled on themselves at one end. and hooked over the channel flanges, and bent at right angles at the other end and hooked behind the blocks 29. The vertical members 35 and 36 are anchored and secured to the members 34 (and hence to V the wall 26) by means of Z-shaped metal clips 38 bolted fast to the channel webs and taking over the I-flanges,which, as here shown, abut against the edges of the channel flan es.

A shown, there are a number of horizontal metal air ducts or conduits 40 built into the furnace wall at and just adjacent the front portion of the combustion chamber, and extending from the outside of the wall 26 clear across the interspace 27 and through the wall 25. These ducts 40 have swinging control and regulating dampers 41 at their outer ends, and serve as a means of admitting outside air directly into the descending fuel stream at the front of the combustion chamber, to aid combustion and protect the wall in some degree. As shown in Fig. 5, the height and width of these ducts 40 correspond to the height of and distance between adjacent blocks 30 in certain wall courses, and they are arran ed in horizontal rows as substitutes for some or most of the blocks 28 and 29 in such courses.

At the rear of the combustion chamber, the outer wall 26 has an air intake opening 43 controlled by an interconnected gang of slatlilre bi'it-terfiy dampers 44, mounted in a metal frame 45- set in the wall. By virtue of the vertical and horizontal intermural passages and communications described above, the air entering through the opening 43 can pass and circulate everywhere throughout the interspace 27. In some, at least, of the ducts 40, there are upper and lower openings 46 directly in line with the corresponding vertical passages 31. Thus air admitted and circulated through the opening 43 and the interspace 27 can be admitted to the front of the combustion chamber through its inner wall 25, so as to cool the inner wall and preheat the air to improve the efiiciency of combustion.

Through the lower portion of the front combustion chamber wall there are cleanout openings 47 (with a suitable closure) for removal of ashes etc. from time to time; and higher up, above the water screen, are similarly equipped cleanout openings48 for removal or dislodgement of ash or slag accumulating on the tops of the water tubes.

, Fig. 6 shows a modified construction wherein the bonding tie blocks 50 extend clear through both inner and outer walls 25 and 26. As here shown, they are of T-shape, in plan, with the cross-stroke of the T outward. Between inner ends of adjacent blocks 50 are a couple of longitudinal inner wall blocks 28, while between their outer ends are single longitudinal outer wall blocks 29. This construction gives vertical flues 31 somewhat wider latitude lengthwise of the wall than does that of Figs. 1 to 5. The ducts 55 are of about the same horizontal transverse dimension as the ducts 40 of Figs. 1 to 5, so

that they do not exactly replace any regular inner or outer wall blocks 28 or 29, and special blocks (such as 56) must, therefore, be employed with them. Accordingly, each duct 55 has an open cell or portion of the wall space 27 surrounding it on all four sides, and is prov ded with openings 57 in its sides, as

well as with the openings 46 in top and bot in each course are short enough to be overlapped by the abutting ends of the inner wall blocks 28 between the blocks 50 to either side.

These shorter'tie blocks 59 need not be of extremely refractory material.

In Figs. 8 to 11, each of the cross bonding tie blocks 60 and6l extending between the inner and outer walls 25 and 26 forms part of one wall only, without going beyond the interspacial surface 7 of the other wall. As shown, these blocks 60 and 61 are of T-shape in plan, and in each horizontal course they are alternately arranged with their narrow portions between the blocks 28 or 29 of inner or outer wall 25 or 26, respectively. If preferred, only the inner tie blocks 60 need be of extremely refractory material. In the corners, the ends of inner wallblocks 28 fit into reentrant angles in a special extremely refractory corner block 62. As indicated in Fig. 10, each vertical series of tieblocks is built up solid, with inward and outward turned an outer-wallstructure, an inner refractory wall structure, members bonding said structures together in spaced relation and being also spaced from each other to provide vertical and horizontal air passages, and airinlet conduits in the spaces between bonding members and extending through both wall. structures, said conduits having external control valves. 7

3. In a furnace of the character described, an outer wall structure, an inner refractory wall structure, members bonding said struc tures together in spaced relation and being also spaced from each other to provide verti cal and horizontal air passages, and air-inlet conduits in the spaces between bonding members and extending through both wall structures, together with air inlet means to the wall passages and means of communication from said passages into said conduits.

In testimony whereof, I have hereunto signed my name.

VIRGINIUS z. GARACRISTL blocks 60 and 61 in alternation. .Each series 7 I forms, therefore, a very elfective buttress or strengthening rib for each wall and for both walls together. As shown in Fig. 11, the outer wall 26 may be reinforced and stiffened with upright channel members-63 arranged back to back, with cap or bridge plates 64: across them and anchor bolts 65 between them whose heads 66 lie in recesses in theouter blocks 29.-

Thus. the verticalmembers 63 are anchored directly to the outer wall, and horizontal reinforcing members may be dispensed with.

What I claim is:

1. In a furnace of the character described, an outer wall structure, an inner refractory wall structure, members bonding said structures together in spaced relation and being also spaced from each-other to provide verti-' cal and-horizontal air passages, and air-inlet conduits in the spaces between bonding members and extending through both wall structures.

2. In a furnace of the character described, 

